package com.atguigu;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

/**
 * @Author lizhenchao@atguigu.cn
 * @Date 2021/2/10 19:33
 */
public class HashSetDemo {
    public static void main(String[] args) {
        final Set<Long> set1 = new HashSet<>();
        set1.addAll(Collections.singleton(1L));
    }
}
